乳酸菌發酵豆漿脫脂牛奶預防胃黏膜損傷之評估

Abstract

研究指出，乳酸菌可改善腸胃道健康，並能夠提高胃黏膜之完整性。本研究欲建立一動物急性胃部黏膜損傷模式，並進一步探討乳酸菌發酵豆漿脫脂牛奶對於胃部保護之功效評估。實驗使用不同比例之豆漿及脫脂牛奶製備 Lactobacillus plantarum NTU 102 發酵豆漿脫脂牛奶。其中以 75% 豆漿與 25% 牛奶為基質發酵 24 小時後，L. plantarum NTU 102 乳酸菌數可達 2.5 × 109 CFU/mL。分別將 Lactobacillus paracasei subsp. paracasei NTU 101 與 L. plantarum NTU 102 發酵豆漿脫脂牛奶製成凍乾粉，於 4 oC下儲藏 180 天，進行儲藏安定性試驗。凍乾粉之乳酸菌數可維持在 109 CFU/g，pH 值及可滴定酸度呈現穩定狀態。並以文獻中指出之 Shay’s (以手術進行幽門結紮) 、鹽酸、酒精、酸化酒精及 indomethacin 等方法結合活體幽門結紮進行大鼠急性胃黏膜損傷，以幽門結紮合併酸化酒精組在實驗操作過程、胃液樣品採集及評估項目之分析，除可有效誘發胃部損傷外，實驗數據之穩定性優於其他試驗組。將此模式應用於評估發酵豆漿脫脂牛奶預防胃部黏膜損傷之評估，連續餵食 L. paracasei subsp. paracasei NTU 101 或 L. plantarum NTU 102 發酵豆漿脫脂牛奶 28 天，可抑制幽門結紮合併酸化酒精誘發急性胃部黏膜之損傷、降低血液及胃黏膜脂質過氧化物濃度、提升黏膜超氧歧化酶 (superoxide dismutase, SOD) 活性，並可促進黏膜保護物質前列腺素 E2 (prostaglandin E2, PGE2) 之合成。此研究結果表示，乳酸菌發酵豆漿脫脂牛奶具有保護胃部黏膜之潛力。

Lactic acid bacteria (LAB) are reported to improve gastrointestinal health. Furthermore, some reports indicate LAB and their fermented products can effectively enhance the gastric mucosal integrity. The objective of this research was to evaluate the effect of fermented soy-skim milk of LAB on mucosal integrity in gastric mucosal lesion rat. This study used Lactobacillus paracasei subsp. paracasei NTU 101 and Lactobacillus plantarum NTU 102 as a starter to discuss the optimal mix ratio of soymilk and milk. It showed that the cell numbers of L. paracasei subsp. paracasei NTU 101 and L. plantarum NTU 102 fermented in 75% soymilk and 25% milk (optimal condition) after 24-hr cultivation were achieved 1.2×109 CFU/mL and 2.5×109 CFU/mL, respectively. After the shelf-life (180 day, 4oC), the cell numbers of freeze-dried powders from L. paracasei subsp. paracasei NTU 101 and L. plantarum NTU 102 fermented soy-skim milk were maintained at 1×109 CFU/g; variations in pH and titratable acidity were slight. Pylorus ligation combined acidified ethanol was not only able to induce acute gastric lesions, but also get more stable data with collection of gastric juice, experimental operation and parameters of gastric lesion than others in this study. Pylorus ligation combined acidified ethanol treatment was used as animal model of gastric lesion. Experiment groups were fed with RO water (as control), commercial yogurt, unfermented soy-skim milk, L. paracasei subsp. paracasei NTU 101 and L. plantarum NTU 102 fermented soy-skim milk for 28 days, respectively and the preventive effects in the rat of gastric lesion were evaluated. LAB fermented soy-skim milks were resulted in reducing gastric lesion index, gastric lipid peroxides and serum lipid peroxides. They also enhanced the activity of superoxide dismutase (SOD) and cytoprotective prostaglandin E2 (PGE2) synthesis. This finding may indicate that LAB fermented soy-skim milks (109 CFU/day) are the potential food for the protection of gastric injury.